Circular knitting machine



May 2, 1933. W. BREWIN CIRCULAR KNITTING MACHINE Filed Dec. 12, 1931 5Sheets-Sheet 1 $5 1:71; & 3a Inventor Wig" I 'edLBI main,

fittorne ys y 1933. w, BREWHN 1,907,34 1

CIRCULAR KNITTING MACHINE" Fil ed Dec. 12, 1951 3 Sheets-Sheet 2Inventor l'edflrewiw,

wwizz' fiftorneys Patented May 2, 1933 UNITED? STATES PA/TENT OFFICEWILFRED BREWIN, or LEICESTER, nNeLAivn CIRCULAR KNITTING MACHINEApplication filed December 12, 1931, Serial No. 580,699, and in GreatBritain December 16, 1930. V

This invention relates to circular knitting machines and has particularreference to that type of machine which embodies a plurality of yarnfeeders controlling a plurality of yarns, which may differ from oneanother in nature and/orcolour, and adapted to be moved into and out ofyarn feeding positions to produce horizontal bands or stripes ofdiffering appearances in the fabric.

1 This invention is concerned with circular knitting machines having aplurality of changeable yarn feeders'as above and means for separatelytrapping the yarn appertaining to each feeder upon the feeder beingwithdrawn to an inoperative position.

' In many types of circular knitting machines having changeable yarnfeeders it has hitherto'been customary to provide a device in which allof the yarns are trapped as they are Withdrawn from being fed to theneedles.

The disadvantage of a trapper which is common to a plurality of feedersis, however, experienced when it is desired to release a yarn therefromand re-introduce said yarn to the needles, since it frequently happensthat when a yarn to be re-introduced is'withdrawn from the said trapper,the said yarn inadvertently withdraws one or more of the other yarnsfrom the trapper. The inadvertently withdrawn yarns fail to be knittedby the needles when their feeders are subsequently moved to the feedingposition and the fabric is pressed off from the needles. The primaryobject of this invention is to provide improved means for separatelytrapping the yarns appertaining to a plurality of changeable yarnfeeders as above with a View to enabling an increased number of saidfeeders to be selectively moved into and out 40 of thread feedingpositions during the production of a knitted article and, consequently,an increased number of horizontal striped patterns to be produced in thesaid article. A particular object of the invention is to provide meansfor. enabling an increased number of horizontal'striped patterns to beknitted into ribbed tops for stockings and socks, on a circular ribknitting machine.

' According to the. present invention in a circular knitting machine ofthe type set forth a trapping element is associated with each orselected ones of the yarn feeders and means are provided whereby when afeeder is moved from its feeding to its inoperative position, theassociated trapping element is automatically moved to a position to trapthe thread or threads adapted to be fed by the said feeder.

Circular knitting machines embodying a plurality of changeable yarnfeeders have 69 hitherto been provided which incorporate a separatetrapping member for the yarn of each feeder and means for operating thesaid trapping member to trap the yarn when its feeder is withdrawn froma feeding position. In such machines, however, the trapping members havehad no movement relatively to the feeders, apart from their smallope-nmg and closing or trapping movement.

The yarn trapping device according to the present invention may beadapted to be moved radially in regard to the needle circle and thedifferent yarns may be trapped ,between different contiguousfaces ofseveral adjacent trapping elements. 7

A further feature of the present invention consists in providing aplurality of adjacent spring pressed trapping members, one yarn beinggripped between each trapping member and its neighbouflan'd mechanism-tomove the assembled trapping elements over the needle circle so that anygiven yarn raised from its feeding position by the operation of a yarnfeeder is caused to be engaged by a particular pair of said trappingmembers. i I f Conveniently the mechanism for displacng the trappingmember in relation to the needle circle operatesintimed relation withthe mechanism for moving. the yarn feeders into and out of the feedingposition;

In order to facilitate the individual trapping'of the yarns means areprovided'for opening the selected trappingelement to receive thewithdrawn yar A relatively stationary intermittently operating cuttingdevice common to all of the said yarns is also provided. I

For the purpose of more fully describing the nature of this invention,reference will now be made to the accompanying drawings wherein Figure 1is a front elevation of part of a circular rib knitting machine to whichthe present invention is applied.

Figure 2 is a rear elevation illustrating some of the principal parts ofthe invention.

Figure 3 illustrates in detail a composite yarn trapping member providedin accordance with this invention.

Figure 3a illustrates a modified construction of trapping member.

Figure 4 is a plan view ofthe said trapping member and certain of itsassociated operating members.

Figure 5 is a detail elevation of the yarn cutter. 1

Figure 6 is adetail plan view illustrating the yarn cutter operatingmechanism, and

Figure 7 is a detail plan view of a cam plate and yarn feeder housingshown in elevation in Figure 1.

By way of example only, the invention will be described as applied to acircular rib knitting machine adapted for the production of rib tops forchildrens socks and stockings.

In this machine four yarn feeders or guides 1 are provided and each ofthese feeders, when in its lowered position, is adapted to feed its yarnbetween the open hooks of the raised cylinder needles 2 and theforwardly projected dial or rib needles 3, in the well known manner.Means hereinafter described, are provided for moving selected of thesaid feeders 1 into and out of the feeding position to providehorizontal striped patterns in the sock or stocking top belng produced,the said feeders controlling yarns of different colour or nature.

The needle cylinder 2a and the rib dial 3a are stationary and the yarnfeeders 1, mechanism directly associated therewith, needle operating'cams 2b and 3b and the yarn supplies, rotate.

he yarn feeders are pivoted upon a hori- 'zont-al spindle 4 whichhas'its extremities located in side plates 5 of a rectangular housingsupported by a bracket 6 from the cylinder needle cam box 26. The saidfeeders are normally retained in their raised inoperative position bycoiled springs 7, but when lowered to the feeding position,.are engagedby spring influenced pivoted catch levers 8 and retained in the feedingposition until the said levers 8 are pivotaxlly displaced.

The movement of the feeders into the operative position'iseifectedthrough horizontal thrust rods 9,0ne of which is provided foreach feeder. These rods are positioned at different heiglitsand areslidably supported in gablock mounting 10, the inner extremity ofthesaid thrust rods being bent, where necis rotatably mounted.

essary, to engage with the upper parts of the pivoted extremities of thefeeders.

The selection of the feeders is effected by a non-rotating butvertically adjustable cam plate 11 mounted upon the upper extremity of avertically slidable spindle 12 which is supported in a bracket 13 andpasses below the frame 14 in which the cam box 2?) The cam plate 11 isnormally retained in its lowermost position, whereat it will not engagethe thrust rods 9, by a ,coiled spring 15 and the lower ex tremity ofthe spindle 12 rests upon the forwardly projecting extremity of an arm16 secured to a shaft 17 rotatably mounted at the rear and side of themachine. A second arm 18 projectsforwardly from and .is secured to theshaft.- This latter arm 18 is adapted tobe engaged by studs 19 ofdifferent heights carried by an intermittently traversing chain 20 atthe side of the machine, torotate the said shaft 17 and raise the arm 16and spindle 12. The arrangement is such that according to the particularheight of stud 19 whichengages the lever 18, the spindle 12 and camplate 11 is raised to a predetermined height whereat the cam plate is inthe path of a selected thrust rod 9 and, as the said rod is carriedaround, it engages with the cam plate, is slid. thereby and lowers itsfeeder. into theoperative position to be re tamed by one of the catchlevers 8. Slidably mounted upon the upper part of the bracket 13 is ahorizontal bar member 21 having at its inner extremity a cam portion 21aand at its other extremity a bevelled surface 21?). This surface isadaptedto be engaged by a bevelled surface 22a provided on a member 22extending vertically downwards .from the cam plate 11,.and whenthe saidcam plate is raised to a predetermined height to select a feeder foroperation, as above described, the relative movement of the bevelledsurfaces 21aand 2200 causes the member 21 to'slide towards the needlecylinder and positions the" cam 21a. in the path of the rotating feedercatch levers 8. By this means the catch levers 8.are pivoted to releasethe feeder which is in operation. The sequence and timing of operationsin the int'roduction and withdrawal of the yarn feed.- ers will behereinafter described. Mechanism for selectively trapping and forcutting the withdrawn yarn and for releasing and cutting the introducedyarn, in 1 accordance with this invention, will now be described. 7

A composite yarn trapping member 23 is mounted forhorizontal slidingmovement in guides 24, see .Figs. 2, 3 and 4, on the rear side ofthefeeder housing 5 and is carried around the machine with thesaidhousing. 7

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posed adj acently positioned plates 25. These plates are accommodated ina slot 23a in the trapping member and are pressed together by a shortcompression spring 26, see Fig. 3. Each pair of the plates 25constitutes a trapping element for one of the yarns appertaining to thefeeders 1, each of the said yarns being adapted to be received andretained between a pair of the adjacent plates 25.

' The trapper member 23 is normally retained in its innermost positionby a coiled spring 27. On the upper surface of the said trapper member,at a position substantially midway in its length,an upwardly projectingpin 28 is provided adapted to be engaged by an arm 29, carried at theupper extremity of a vertical rotatably mounted spindle 30. I Thebracket 31 in which the spindle is mounted is secured to and rotateswith the cam box 2a and at the lower extremity of the said'spindle astepped projecting member 32 is secured, the said member being adaptedto engage with a second non-rotating cam plate 33. The cam plate 33 isnormally positioned below the stepped member 32 and is adapted to beraised to predetermined heights, to engage with selected of the steppedportions of the said elements. The arrangement is such that as the camplate 33 is raised to engage with the higher stepped portions of themember 32, the spindle 30 is rotated to a greater extent and effects,through the arm 29, comparatively extensive sliding dis placement of thetrapper member 23. When the cam plate 33 engages with the lowerprojections on the member 32 reduced sliding displacement of the trappermember is effected.

The cam plate 33, see Fig. 1, is carried at the upper extremity of aspindle 34 which rests upon an arm 35 carried by and'projectingforwardly from a second horizontal shaft 36 extending at the rear andside of the machine, the said shaft also carrying a second forwardlyprojecting arm or lever 37 adapted to be engaged by a second row ofstuds 38 of varying height provided on the chain 20 from which selectionof the feeders 1 is effected. as before described. The engagement of thevarying heights of studs 38 with the arm 37 effects rotation ofthe shaft36 and, through the arm 35 and spindle 34, raises the camplate 33 toengage with the different stepped portions of the member 32.

In order to facilitate the passage of a with drawn yarn between itsappointed trapping element the lower edges of the trapper plates 25 maybe slightly bevelledas shown and means may be provided for openingthe-said trapping element simultaneously with the rais ng of thecorresponding yarn feeder.

To effect this a horizontal lever 39, Figs. 2 and 4, may be pivotallymounted at its one extremity to a bracket 40 conveniently secured to aboss 41 encircling the vertical shaft 42 which carries the dial needlecams 3?). At a position substantially midway in the length of the lever39 a screwed pin 43 is secured, the one extremity 43a of the said pinbeing pointed and adapted to be forced between the plates 25 adapted totrap the withdrawn yarn. Thepin 43 is normally retained withdrawn by asuitably anchored coiled spring 44 and the lever 39 and pin 43 areadapted to be forced inwardly, to separate the trapping plates againstthe influence of the said sprlng, by a pivoted substantially triangularplate 45, Figs. 2 and 6, a downwardly extending portion 45a of the saidplate carrying an adjustment screw 46 which bears against the said lever39. The

plate 45 is pivoted at 47 and carries a projecting element 48 adapted toengage with an upstanding cam 49 mounted on the vertically adjustablecam plate 11. The plate 45 is normally retained outwardly extending by acoiled spring 50.

A cutting device 51, which is common to all of the yarns and is retainedstationary relatively to the trapping element, is positioned at the rearof the trapper member 23, the blades of the device being in the natureof scissors and shaped to allow the pin 43 to pass therebetween, seeFig. 5. The operation of the cutter at the required time is effected byan inclined cam portion 52 adjustably secured to the pivoted plate 45,the said inclined cam, upon pivotal displacement of the said plate bythe cam 49, imparting pivotal movement to the cutter blade 51a against aspring 53.

The sequence of operations in the withdrawal, selective trapping andsevering of a yarn and the selective introduction and the severing ofanother yarn will now be described.

A stud 19 of a predetermined height raises the cam plate 11 to a heightwhereat it is in the path of that rod 9 which appertains to thefeeder 1selected for introduction. Simultaneously the bar 21 carrying the cam21a is slid forwardly into the path of the catch lovers 8. Uponreference to Fig. 7, however, it will be seen that the selected rod 9 isengaged by the forward edge 11a of the cam plate 11 to lower its feederto the operative position, prior to the catch levers 8 riding over thecam 21a to release the feeder in operation, and thus the usual overlapof the introduced and withdrawn yarns is obtained.

Simultaneously with the displacement of the cam plate 11 by a stud 19,one of the studs 38 of a predetermined height'engages with the arm 37and raises the cam plate 33 into the path of the appropriate steppedportion of the member 32'. Consequently, upon the rotation of the member32 around the machine, it engages with the positioned cam plate 33 androtates the spindle 30 and arm 29 to cause the trapper member 23 toslide rearwardly and position the trapping element 25 appertaining tothe yarn being withdrawn, directly above the needle circle, so that thewithdrawn yarn, as it extends from the raised feeder to the point atwhich it is connected to theneedle circle, and as the feeder and trappercontinue to travel around the machine, passes into the said trappingelement and is retained ready to be engaged by the needles when the saidfeeder is again lowered to its operative position.

T he selected trapping element is opened to facilitate the entry'of thewithdrawn yarn therebetween, by virtue of the projecting portion 48engaging with the cam 49, rotating the plate and causing the extension45a to force the pointed pin 43 between the plates 25 comprising thesaid element. Simultaneously, the rotation of the plate 45 causes thecam 52 carried thereby to operatethe cutter 51 and severthe portion ofwithdrawn yarn which extends from the needles to the trapper. Bysuitably .positioning and operating the trapper 23 and cutter 51, theloose severed end of yarn may be made so short that it will be drawninto the fabric and rendered invisible.

As the feeder appertaining to the newly introduced yarn is lowered. intothe operative position by the selected rod 9, the yarn, which havingbeen previously trapped extends between the feeder and the trapper istaken by the cylinder needles and is drawn over the open projectedhoolrs of the dial needles. The end portion of the introduced yarn,which now extends from the needle circle to the trapper, passes beneathand to the rear of the trapper. as the said trapper continues to travelaround the stationary needles, and the said end ofyarn passes betweenthe cutters, which have been opened to receive the withdrawn yarn andthe ends of both the withdrawn and re-introduced yarns are severed atthe one operation of the cutter[ It may be found desirable, particularlyin connection with those trapping elements which are positioned aconsiderable distance from their feeders, to provide means for openingthe said trapping elements to release their yarns when. their feedersare lowered into the operative position. Such means are shown inconnection with the trapper element 25a which appertains to the furthestremoved feeder 1a, see Figs. 1 and 4. A

.' spring pressed pointed pin 54 is adapted to be thrust downwardlybetween the trapper element 25a to separate the blades 25 thereofagainst the resistance of the spring 26 when a lever 55 and peg 56 ispivoted to deflect a flat spring 57 which bears against the said pin 54.An inclined surface 55a at the one extremity of the lever 55 is adaptedto be engaged by a horizontal pivoted lever 58 to pivot the said lever55, and the horizontal lei ver .58 is itself pivotally displaced about apin 58a by virtue of a lower projecting part 59 at the outermostextremity of the said lever "58 engaging with a further cam 60 securedto the vertically adjustable cam plate 11. The arrangement is such thatthe projecting part 59 will only engage with the cam 60 to open thetrapping element 25a, when the cam plate 11 has been raised to itshighest position to engage with highest thrust rod 9 and lower thefeeder 1a into its operative position.

It will be understood that upon the severing of each introduced yarn, ashort length of yarn is left in the traping element. These lengths ofloose yarn gradually work their way upwardly between the plates 25 untilthey reach apertures 25b'provided by side grooves at the upper parts ofthe said plates, the said ends then fall away from the trapper and maybe collected by the brush customarily provided to sweep'the latches ofthe dial needles.

Further, a plate, such as 61 in Fig. 1, conveniently secured to the bar23, may be provided in connection with all or certain of the trappingelements to determine the height at which the yarns are trapped and cut.

In a modified form of trapping member, see Fig. 8a, each of thespring-pressed plates 25 which constitute the trapping elements, isindependently pivoted at its upper extremity 250 to a part 28a carriedby the bar 23. One of the advantages of this construction is that whenthe pin l3 is forced between the selected trapping plates 25 the saidplates are opened wider, at their lower parts toreceive the withdrawnyarn than are the plates in the construction illustrated ,in Fig. 3 andthe reception of the yarn between the said plates is therefore moredefinite. In this construction one or more of the trapping plates 25 mayhave an upper cranked extension 25d adapted to be engaged by adescending member such as 56 to open one or more of the trappingelements for the purpose of receiving or releasing one or more of theyarns.

.Vhereas, as previously stated, it has hitherto only been possible toprovide a very limited number of yarn changes in a circular rib knittingmachine, it will be appreciated that the number of changes renderedpossible by the present invention is limited only by the size of thevarious parts of the invention and the parts of the machine with whichthey co-operate.

It is of importance to note that the present invention isnot limited tocircular rib machines, but may with advantage be applied to plaincircular knitting machines, in connection with which the presentpractice of trapping, cutting and accumulating changed yarns at thecentre of the machine has long been considered a great disadvantage.

I claim 1. In a circular knitting machine, a plurality of yarn feeders,mechanism for lowering and raising said feeders into and out of yarnfeeding position, a yarn trapplng member embodying a plurality oftrapping elements pressed towards one another by means of a spring andbetween adjacent ones of which a yarn is adapted to be trapped, meansfor moving the trapping member as a whole radially of the needle circle,and said means operating in timed relation with the mechanismcontrolling the movement of the yarn feeders in order that when aparticular feeder is raised to the non-feeding position the yarn trapperis adjusted radially to trap the yarn fed by said feeder.

2. In a circular knitting machine, a plurality of yarn feeders, meansfor moving said feeders into and out of yarn feeding position, acomposite yarn trapping member embodying a. plurality of yarn trappingplate members, spring means for pressing the said plate memberstogether, each adjacent pair of the said plate members constituting aseparate trapping element for a withdrawn yarn, and means for moving thesaid trapping member to position a particular trapping elementso that itwill trap the yarn appertaining to a feeder with which it is associatedwhen the said feeder is withdrawn from a feeding position.

3. In a circular knitting machine, a plurality of yarn feeders, meansfor moving said feeders into and out of yarn feeding position, acomposite yarn trapping member embodying a plurality of yarn trappingplate members, spring means for pressing the said plate memberstogether, each adjacent pair of the said plate members constituting aseparate trapping element for a withdrawn yarn, apertures between thesaid plate members at predetermined positions to assist in clearingaccumulated yarn between said plate members, and means for moving thesaid trapping member to position a particular trapping element so thatit will trap the yarn appertaining to a feeder with which it isassociated when the said feeder is withdrawn from a feeding position.

at. In a circular knitting machine, a plurality of yarn feeders, meansfor moving said feeders into and out of yarn feeding position, acomposite yarn trapping member embodying a plurality of yarn trappingplate members, spring means for pressing the said plate memberstogether, means for moving the said trapper member to position aselected trapping element so that it will trap the yarn appertaining tothe feeder with which it is associated when the said feeder is withdrawnfrom a feeding position, and means for forcing a member between thespring-pressed plates constituting the select ed trapping element toopen the said element and facilitate the reception of the yarntherebetween or the release of yarn therefrom.

embodying a plurality ofyarn trapping plate members, spring means forpressing the said plate members together, each adjacent pair of the saidplate members constituting a separate trapping element for a withdrawnyarn, pivoted lever mechanism for moving the said trapping member topredetermined variable extents to position a particular trapping elementso that it will trap the yarn appertaining to a feeder with which it isassociated, an adjustable relatively rotatable cam for operating saidpivoted lever mechanism and a patterning member, which also moves theyarn feeder into and out of operation, for controlling the said cam.

7. In a circular knitting machine, a plurality of yarn feeders, meansfor moving said feeders into and out of a yarn feeding position in anyorder, a plurality of yarn trappers one allocated to each feeder, meansfor moving all of said trappers bodily and in unisonin relation to thefeeders, when a feeder is moved to a non-feeding position, to a positionwhereat the appropriate trapper is placed to receive the yarn from thatfeeder.

8. In the combination of claim 7, a trapper opener that is common to allof the trappers and is operable upon any trapper that is brought totrapping position by the said trapper-moving means.

9. In a circular knitting machine, a plurality of yarn feeders,patterning means for .moving said feeders in any desired sequence intoand out of yarn feeding position, a plurality of yarn trappers one foreach feeder that are movable en masse in relation to the needle circleand the feeders, and patterncontrolled means, operable when any feederis moved to a non-feeding position, to move said trappers and therebybring the appropriate one to a location at whichthe yarn from suchfeeder is caught in it.

10. In a circular knitting machine, a. plurality of yarn feeders, meansfor moving said feeders into and out of yarn feeding position, a trapperunit comprising a plurality of trappers, one for each feeder, which unitis movable in a rectilinear path through variable distances to bring oneor other of themto a trapping position, and means, operable when anyfeeder is moved out of feeding po sition, to move said trapper unitthrough the required distance to bring the appropriate trapper totrapping position.

11. In a circular knitting machine, a plurality of yarn feeders, meansfor lowering and raising said feeders into and out of yarn feedingposition, a yarn trapping element associated with each of said feeders,means for movab-ly mounting said elements above the needle circle, andmeans for moving said elements across the said needle circle so thatwhen a feeder is raised from a feeding to a non-feeding position itsyarn will automatically be engaged by the trapping element associatedwith the said feeder.

' In witness whereof I have signed this specification.

WILFRED BREWIN.

